Isotopic disequilibrium in mafic plutonic systems
Best insight from top research papers
Isotopic disequilibrium can occur in mafic plutonic systems. The isotopic compositions of melt, source, and restite can differ significantly due to processes such as partial melting and crystallization. In some cases, the Hf isotope compositions of bulk-rock samples may be different from the melt-precipitated zircons within them, indicating isotopic heterogeneity within the system . Additionally, simple restite separation from a single protolith can produce magmas with a range of Sr-Nd-Hf isotope compositions, independent of source variation . Isotopic disequilibrium can also be maintained between phenocrysts and matrix in silicic magmas and mafic inclusions, due to the short time-scale for melting and crystallization in basalt-induced crustal melting . Furthermore, isotopic compositions can change significantly during the evolution of silicic rocks, as observed in the Bandelier Tuff and associated rocks .
Answers from top 5 papers
More filters
| Papers (5) | Insight |
|---|---|
12 Citations | The paper discusses thallium isotope fractionation during magma degassing, but it does not specifically mention isotopic disequilibrium in mafic plutonic systems. |
| The paper does not provide information specifically about isotopic disequilibrium in mafic plutonic systems. | |
Open access 07 Jan 1990 1 Citations | Isotopic disequilibrium can be maintained between phenocrysts and matrix in mafic plutonic systems. |
15 Citations | The paper discusses isotopic disequilibrium in granitic systems, but does not specifically mention mafic plutonic systems. |
| The paper discusses isotopic disequilibrium in the Mt. Perkins Pluton, Arizona, suggesting a two-stage magma mixing-commingling process. |
Related Questions
Isotop effect in permeability4 answersThe isotopic gas method is used to measure permeation of gases through a material. The method involves forming a mixture of isotopic gases in a mixing enclosure and filling a permeation enclosure with this mixture. The permeation enclosure consists of two chambers separated by the material. The isotopic gases that permeate through the material are then analyzed in the second chamber to calculate the permeation of each target gas. Additionally, the effect of anisotropy on permeability measurements was investigated using a numerical simulation model. The results showed the clear effect of anisotropy on probe permeameter measurements, which can be used to evaluate permeability anisotropy from a few steady-state flow rate and pressure drop measurements.
Isotop effect in fusion plasma4 answersThe isotope effect in fusion plasma refers to the impact of the atomic mass of the main ion species on plasma transport and confinement. Experimental analyses have shown that the global confinement of energy, momentum, and particles in ELMy H-mode plasmas exhibits a strong and favorable dependence on the atomic mass of the main ion species, contrary to expectations based on local gyro-Bohm scaling. This dependence is also observed in momentum transport and particle confinement. Nonlinear local gyrokinetic analysis suggests that collisions, ExB shear, and plasma dilution with low-Z impurities play a role in accounting for the observed anti-gyro-Bohm heat flux. In L-mode plasmas, a weaker positive isotope scaling has been found. The importance of multiscale physics in unraveling the isotope effect has been demonstrated through the study of local turbulence and long-range correlations in hydrogen and deuterium plasmas.
What is equilibrium isotope fractionation?5 answersEquilibrium isotope fractionation refers to the partitioning of isotopes between different phases or reservoirs at thermodynamic equilibrium. It is determined by the difference in free energy between the phases containing different isotopes of the same element. The equilibrium isotope fractionation constant depends on temperature and can be estimated using various expressions derived from the thermodynamic properties of molecules. The force constant and bond length of the molecules play a significant role in determining the magnitude and direction of the fractionation. Computational methods based on quantum mechanics, such as density functional theory, can be used to model and predict equilibrium isotope fractionation in different systems. The knowledge of equilibrium isotope fractionation is important for understanding geochemical processes and can be applied in various fields such as environmental science and planetary science.
What are the stable isotope fractionation models for planetary forming processes?5 answersStable isotope fractionation models for planetary forming processes have been developed to understand the composition and evolution of planetary bodies. These models consider factors such as accretion, differentiation, and core formation. The isotopic signatures of elements like iron and ruthenium are used to decipher the isotopic nature of the Earth's accreting material and the composition of meteoritic material. The models also explore the effects of gas accretion rates and migration rates on the formation of planetary systems, including the distribution of masses and semimajor axis of extrasolar planets. Additionally, mathematical models have been developed to simulate carbon isotope fractionation during thermal cracking of organic material, providing insights into petroleum formation and isotope fractionation during cracking reactions. These models help improve our understanding of the processes involved in planetary formation and the isotopic composition of planetary bodies.
What are the types of stable isotope fractionation models in planetary forming processes?5 answersStable isotope fractionation models in planetary forming processes include collisions between rocky planetesimals, planetary embryos, and/or proto-planets causing significant losses of moderately volatile and common elements. Another model focuses on carbon isotope fractionation during thermal cracking of n-paraffins, which can induce isotopic inhomogeneity among resulting distributions. Isotope fractionation mechanisms in planetary atmospheres involve atmospheric escape, isotope substitution effects on equilibrium constants, photolysis rates, and chemical reaction rates. Variability of iron isotopes among planetary bodies may reflect their accretion or differentiation histories, with nickel potentially controlling iron isotope signatures. High-precision isotopic data reveal that the Earth's accreting material is most similar to enstatite meteorites, but the late veneer of material accreted to the Earth did not originate in the outer Solar System.
What are the stable isotope fractionation models for planetary forming processes?”?2 answersStable isotope fractionation models for planetary forming processes have been developed and studied by various researchers. One model focuses on carbon isotope fractionation during thermal cracking of n-paraffins, which has been calibrated based on laboratory cracking experiments on n-octadecane. Another model suggests that variability of iron isotopes among planetary bodies may reflect their accretion or differentiation histories, with nickel potentially controlling iron isotope signatures. High-precision isotopic data reveal how the composition of meteoritic material changed over time, providing insights into the Earth's accretion and forcing revisions of models of its formation. Research has also aimed to constrain the timing and proportions of materials involved in early planetary accretion and differentiation events, using various isotope systems and trace elements. Additionally, a simple model has been developed to compute planetary formation based on the core instability model for gas accretion and the oligarchic growth regime for the accretion of the solid core.